I’m going to have a go at building my own (spare) wheels as I’ve always wanted to have a go.
I’m going with DT 350 SP hubs but torn between 3 rims.

Pacenti TL28 400g 28-23mm
WTB i25 499g 30?-25mm
WTB i25 KOM 420g 30?-25mm

Riding will be, mainly, XC type stuff. No big drops, jumps but a bit of rocky, rooty stuff.
Currently have Flow (not EX) on my other wheels so wanting to build something a little lighter.
Thinking KOM on the front, i25 on the back.
What would you use?

Light Bicycle carbon?

SP spokes are the biggest issue though, PITA to get hold of, and add an extra challenge to the build.

Spokes aren’t a problem, £40 from Germany.
LB rims are £150 more so out of budget.

I think I’d look at Spank Oozy 295s.

My TL28s wer light and kept good shape, but a bit soft when it come to rock strikes..

Have a look at Easton Arc’s…but be quick as they sell out really quickly. CRC have just re-stocked