Small rigid router - Design advise needed

[JAZZCNC]

thats not going to work

no ways you gonna bolt it together so that the rails come out within a decent tolerance ....
have a read about epoxy leveling a frame if you havnt already ?

Depends how it's done. Epoxy leveling isn't the be all and end all solution. I've said this many many times but for a good DIY machine you need to build in as many oppertunity's for adjustment as possible and bolting allows plenty of scope for shimming etc to get machine accurate.
If done correctly then it's actually better than epoxy because you can fine tune to very high tolerence.! Only thing is it takes much more time and patience.

belts aint gonna make it any smoother .... id run a coupler on the two axis' , so much easier and cheaper

Actually can make a huge difference esp on all steel machine that's running analog drives with limited resonance handling. This is actually the main reason to use Belts and the ratio option and flexabilty is just a bonus.

Often folks running direct drive don't realise they have resonance problems and just accept that the speeds and performance they are getting is just the max level they can tune to or achive from there motor/drive setup. When often the reality is that the same motors/drives when run on belts and unaffected by resonance will achieve much higher and smoother performance.