Tim,
It's exciting getting a new tractor and I think you are wise to reach out and ask for input. I have to say I have purchased 3 Kubota tractors, a Kubota track loader & a Kubota Excavator. I have never purchased a Land Pride attachment from a dealer and in fact have never purchased any tractor attachment from any of the dealers that I purchased my tractors from. I don't think Land Pride is bad in any way, in fact I own several Land Pride attachments that I purchased used on Craigslist. I have asked my tractor dealers for attachment pricing on a number of occasions but always found a significantly better deal on new attachments from elsewhere.
I believe that the attachment market is rapidly changing from the model of manufacturers selling through dealers to manufacturers selling directly to end users, this is pricing out the dealers selling attachments unfortunately but it also creates many manufacturers offering good quality innovative products at reasonable prices, with direct delivery to the end users.
My advice would be to focus on your tractor first and what features or accessories should come with the tractor from the dealer. I understand that you want a B2601, with front end loader and maybe a MMM. You should decide what type of tires you want, there is a different cost for each type and some have adjustable track widths too. Then you should decide if you want the rear tires loaded to help give some ballast when you are using the front end loader. You should make sure your FEL has a SSQA to be able to quickly swap from bucket to forks and grapple. I would add a rear work light fitted to the ROPS, this is a low cost add on that is very useful. In my opinion these are your initial decisions to ensure you get your tractor with the correct basics.
The next thing to consider is the 3rd function valve to provide front hydraulic connections on your loader and if you are going to fit any rear hydraulic remotes on the back of the tractor. I honestly believe that this work can be done at any time and will be the same price, if you are not skilled in this area I strongly suggest that you have the dealer who supplies your tractor do this work. These add on's are expensive and are longer term decisions. I just booked 2 of my tractors in at the dealer to add hydraulics this month, prices are the same as when I purchased them 3 years ago. You need to ask yourself do you need these hydraulics in your use? If you do not have budget restrictions I would tell you to fit the 3rd front function and 2 sets of rear remotes. Uses for the front include grapple, land shark tree trimmer, tree / post puller. Uses for rear include top link or top and tilt links, dump trailer, snow blower, angle blade, attachment with road wheel lift etc.
I suggest you sort those decisions out first and see what your remaining budget is for other attachments.
I recommend a set of forks, if you do buy them consider weight but make sure you buy adjustible width forks, I would also buy a forkframe with a headache rack to provide protection. on my smaller loader I use a set of UA 42", I think these would be a good size for your B2601, Land Pride make something similar maybe lighter PFL12 Series. UA fork frame also comes with a receiver mount option, good to move empty trailers.
I see that you want a rotary cutter or brush hog, I think a B2601 will run a 48" unit if you are cutting heavier cover or a 60" unit if it is a lighter model. In the past I purchased my first units on Craigslist found what really worked for me then upgraded to a new model in some cases and never lost more than $50 for any used attachment that I found through Craigslist. I purchased some attachments and sold them as I learned that they did not really do the job I anticipated or that they were just not needed!
An attachment that I would recommend is a rear ballast box, take a look at palletforks.com they make a version that is not expensive and will carry a compact rear load to help you use your loader. I buy bags of gravel and just drop them into the ballast box.
Another low cost attachment I would recommend is a 3pt receiver hitch, this allows you to tow and move things.
I have purchased a lot of large heavy attachments through Everything Attachments and have never been disappointed with their attachments.. For brush hogs I really like Woods equipment and have heavier cutters. I just purchased a very affordable grapple at MTL attachments, they have lots of models for under $1,000 shipped, Everything Attachments makes a very nice light Wicked grapple but you will spend double. A B series does not have the power or weight to rip up the ground too much with a grapple, select a design that fits your needs, ground work, tearing out brush and / or carrying brush and cut wood.
For a tiller I suggest you buy used and try one, you commented that you only have a days work for one, can you borrow or rent one? Again find out what size and type work for you.
I suggest order and spec out your tractor, decide which attachments you must have right now with the tractor, ask your dealer for the must have attachment pricing and compare whats in the market. Wait until you get your tractor to get a feel of using it and it's capabilities before buying more, consider used attachments.
I've made a lot of suggestions, I hope they help you in decision making.
Good luck getting things sorted out.