It's not really an agency, more like several independent girls pooling their resources.  There are reviews of several of the girls here.

In addition to Midwest Beauties, you can try The Rising Sun (located off the capitol square) and The Geisha House (located on E. Washington).  They're both massage parlors and some ladies offer full service.  Whether or not they're worth the effort I don't know... I personally avoid massage parlors.

I've used the services at The Rising Sun about 6 times.  Most of the girls give full service.  $70 for the room, $70 for the service.  No upsells.  And you can ask the girls if they provide a "full program".  Use those words, any other expression will make them a bit paranpoid.

Scarlett give great head (uncovered), Monica is very beautiful, Gina has great tatoos and give a very nice full service with uncovered french.