Well a little King Air training is a start. Here are some at HOU:
American General Corp
BE200, DA2000, HS125-800
Compass Bank
2 X CE650
Hollywood Marine Inc.
BE200
Reliant Energy
BE200, IAI 1124, HS125-800
P-K Charter
BE200, LR35
As a furloughee from a major you may have difficulty with some corporate flight depts. They may see you as someone who will bail back to United or another airline someday. If you are interested in switching career paths and looking for a top-tier FalconCapt type corporate job you may want to look at bridging the gap between 121 and Corporate by doing a little 135 time. A Pt 91 corporate operator may be more likely to look at a guy whose last job was as a 135 King Air Captain than a United FO. The type of flying is closer to what the corporate operator does and it shows an interest in going that route over returning to a major.
Looking for a 135 position is where your 121 experience will help instead of hinder you also. A 135 operator will look at your 121 time and realise that you are familiar with ops specs and all the other paperwork associated with flying for an air carrier. Since there is more turnover in charter than corporate the charter operator is less likely to be turned off by the prosepct of you leaving to go fly for Southwest next year.
Once you have a little time at a charter operator and maybe a corporate type rating the doors will be a lot easier to squeeze through in the corporate world. Flying charter will also mean hanging around in FBOs with corporate guys, meaning great networking time.
Anyway, just my two cents worth. I hope it made sense. I'm rushing because I need to go get ready for my anniversay dinner now or the wonderful Mrs. Flywrite will not be a happy camper!
Good Luck!