Bathroom remodel - hooking drain for new sink into toilet line

[cmac2012]

I'm remodeling a bathroom, it's almost doubling in size. It's in the garden level (built on a hill), it has a slab floor. Will have a new vanity, I figured quickly enough that I'll need to tie the sink drain into the toilet line somehow. Here's a pic of the toilet line as is:



In this pic were my two choices at Home Despot. The upper one is more normal but it's too long for the space I have:



I want to use the one on the bottom. Will be a snap to fit in place. I meant to take a pic of looking down into it. It's a bit odd the way the 2 inch line dovetails into the 3 inch curve. I worry that solids might get caught in it. I've found it referred to as a 90 ELBOW W/HEEL, 3" x 1-1/2". The pic at the site looks like mine but I could have sworn mine was a 2" Would work either way. I just found a 4" elbow with 2" heel that could be better. Just more room to avoid any obstruction.

*EDIT* Oops, I found confirmation finally that I should not use that:



Here's a crude drawing of the room and the opening I've since chiseled into the 'crete:



The previous wall was just to the left of the new vanity. the door right there also. The toilet will be much nicer, a one piece Toto, an elongated - Ultramax ll. It's being spun 90 degrees to the left. I decided to send the sink drain to the toilet line as I want to move it two inches back so I can get that 12" from wall - will go for 12.25, I've gotten way too close for comfort once or twice.

My thought is that the sink is usually run briefly after every toilet use so if anything was lingering in that smaller space, another sort of flush would soon be coming.

But this is sort of weird, I've never seen anything like it done anywhere. Anyone know if this is OK?

The shower used to be in the upper left hand corner. A tub is going in. The shower line too close to the surface to send the sink that way. Wouldn't be able to get good slope.

I'm a half-fast plumber and it's hard to get any subcontractors to come out to a small job, what with all the work going on. So looks like I'll need to do this myself.