Ritchey Commando 29+

After an incredibly spontaneous purchase, that I'm now post rationalising as a very sensible bid to rationalise my bike collection - I've just purchased a Ritchey Commando frame..

It's a proper fat bike with 170mm rear spacing and 135mm at the front with clearance for 26 x 3.8" tyres. However the riding I do just doesn't warrant the full fat thing, so instead I'm going to go half way and put 27.5+ wheels on with 2.8 tyres. I'm hoping that this shouldn't alter the geometry too much, but as I'm entirely new to the world of mountain bikes I probably wouldn't notice anyway.

Planning something along the lines of this:

or this

Currently all I've got is frame, fork, thomson stem/post and the alpkit jones loop bar knock off.

Planning a 1x10 groupset to keep things simple with a microshift/paul thumbie shifter.

Wheels wise thinking wtb 27.5 i40 rims and then wtb ranger tyres 2.8, unsure on hubs

So outstanding questions are:

• any reasons why I can't build wider fat specific hubs, with non-fat bike rims
  
• is the wider Q factor of fat bikes that noticeable?