I'm a huge Robert Rich fan - I have most of his CDs and have even had the pleasure of corresponding with him (very sharp and nice guy).
It sounds like you're into his more melodic stuff, so you should check out Electric Ladder, Gaudi, Geometry, Ylang, and Rainforest.
He also has some collaborations that may be up your alley: Yearning (with Lisa Moskow), Soma & Strata (with Steve Roach) and 3 with Ian Boddy.
The rest of his discography is more ambient, but certainly worth a listen! His 7-hour ambient piece 'Somnium' is particularly impressive.