I'll be building up a first-timers' mountain tandem frame soon, and am curious about some budget fork options.

I don't have high hopes for the POS stock 50mm suspension fork. Ideally, I'd like to get rid of it and install a rigid fork that can handle a 203mm disc brake... and maybe a 20mm thru-axle?

My preferred option is to convert from the stock 26" wheel, and install either a 29" (or even 650b) wheel plus a meaty 2.3 to 2.5" tire, for a little bit of pnumatic suspension.

My secondary option is to stick with the 26" wheel size. I see that DMR has a 20mm thru-axle dirt jump fork that I guess would be suitable for our needs.

I'm looking for any general advice / pointers