So I have a spikes tactical st-15 rifle that im still running the stock CAR handguard on.I want something that i can mount a light and a vertical grip to. I really want to keep it drop in for budgeting reasons so im looking between the magpul MOE (or SL) or the B5 keymod. I'm leaning towards the B5 because of how narrow it looks, and i like gripping the rifle up near  the front sight block. The only problem is the B5 isn't available in the mid length size yet, and they seem to not really have a clear idea of when they''ll be hitting retail locations.

TL;DR summary: Should I wait for mid length B5 handguard,or should I get a Magpul handguard? Any other recommendations I should be looking at?

I haven't used the B5, but used to have the MOE.  I really liked the MOE.  Very sturdy feeling.  Also very comfortable.

B5 told me a couple weeks ago that they were shipping within a few weeks.  Part of the problem with them is that their website is completely out of date and they don't directly sell to the public yet.  They have a couple products I love but aren't well known and can be hard to find (end plate, trigger guard) as most places only sell their stocks.

I've been checking B5's facebook page very regularly waiting for any bit of information about its release. I think i'm just gonna have to be patient.

Have you looked at these?

Midwest Industries

this, I never expected that!

+1 on the MI drop-in.  

A very good value.  Excellent workmanship and good price and color selection.  Not cheap Chinese shit.

I think the MOE stuff is pretty hideous, but certainly opinions will differ, I would look hard at the MI drop in stuff