Both jobs offer something NetJets is probably looking for. I flew both corporate and regional airline and I think it helped a lot getting on with NJA.
I hate to say it, but I would take the job at Skywest. It's probably more stable than your present job, it will introduce you to glass cockpits, you'll gain experience in a higher pressure training environment than you've probably been used to, you'll learn to deal with dispatchers, you'll be operating under regs that are closer to what you'll operate under at NJA.
It will also give you more exposure dealing with a two crew environment. I'm guessing you only have one or two guys you fly with in the Beechjet. Airline flying is vastly different than corporate in terms of crew communications.
I had a similar decision to make 4 years ago when I was flying a Sabreliner. I could either get a typed and fly about 200 hours a year in it, plus a little on the side, or go to Piedmont and fly the Dash about 800 hours a year. I took the job at Piedmont. I was miserable for the last 2 years working there, but I gained skills and tools that I wouldn't have gotten otherwise. I leave for training at NJA tomorrow, so I think I made the right choice. I also think the training I got at Piedmont will give me something to build on at NetJets.
Had I stayed on flying the Sabre, I would not have been in a position to apply with NJA. I'd be short on total time, I wouldn't have seen much in the way of winter ops, sim training, CRM, etc. I would have been happier in the short term, but 4 years of busting it a regional was worth it to get where I am now (or soon will be). Feel free to PM if you have questions.