Rigid forks for change faucet of Planet X xla frame and fork?

So I’ve got a change faucet frame gathering dust and most of the parts to build a mtb based road bike, (flat bars, 29” wheels, slicks and discs) really don’t get on with drop bars so am happy to go with above set up.

But I need some “sus corrected” forks for the faucet which by my calculations will need to be anything above 475mm a2c. As far as I can find it’s either exotic £130 or cheapo eBay £70. Or I go for the xla frame and fork £200

So any thoughts on which might be better? Or other idea?? I’d say £200 was my max budget either way.

If it makes any difference I’m 6’1” and 100kg.