Tandem Cycling - Rigid Dirt-Jump fork for tandem? 29"er conversion?

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 *** 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

I'm looking for any general advice / pointers

Have one selected or made specifically for your intended application by someone with experience riding or building robust, rigid forks for off-road bikes/tandems or multi-seat tandems, e.g., Sherwood Gibson at Ventana USA (www.ventanausa.com), Vicious Cycles (www.viciouscycles.com), Bob Brown (www.bobbrowncycles.com), Dennis Bushnell (www.bushnelltandems.com), Co-Motion (www.co-motion.com), etc...

You could also cover you bases by contact Alex at MTBTandems.com to see what he may have come across as 29ers continue to be popular item.

What sort of riding do you intend to do? How heavy is your team?

The DMR fork is exactly what I was looking for when I had stopping issues with my KHS Sportmania - a nice fork to which one could mount a disc brake. Instead I got a *** 50 mm suspension fork...and that lead to a round of upgrades which culminated in a Marzocci DJ, 20 mm Chub hub and Magura Gustav (all of which somehow found there way onto my son's MTB bike...not sure how that happened). My riding of the KHS changed too. Instead of riding with my oldest daughter from one subdivision to another for soccer, my son and I were riding singletrack in the mountains.

I will probably get a DMR fork when the 3rd daughter is big enough to ride the tandem...

Prairie*boy

Depending on what axel to crown distance you are looking for the rigid Funn fork is another good option. It has clearance for the fattest 29er tires, 20mm axle, is disk compatable and is plenty strong for MTB tandeming. The A-to-C distance is 19". The cantilever bosses are for a 24" wheel or something weird so they are pretty useless.

Here is a link to a review of the fork: http://alwaysmad.com/reviews/showproduct.php?product=110&cat=6

Thanks for everyone's input. Comments posted here by Tandem Geek & Prairie Boy opened my eyes to the expenses I was facing, and I've since regrouped.

The initial frame and fork have come and gone, never having made it out of the box. In its place is a decent used Cannondale tandem with fork, wheel and brake upgrades underway. A bit more than I wanted to spend, but we're getting a great bike out of it.