If you've got the money to spend on a long cycle, go for it, but IMO at your age you don't need it. At its simplest, you're supplementing your natural hGH production, and you're still very young and are probably running at not far from optimal levels. In that sense, I dont' see the point.
I think you should just continue w/ what you're doing. If you've been obese all your life and just going through a dramatic weight loss you might have some trouble w/ tightening up skin (can require surgery) - but if you're not talking about on the order of 100 lb weight loss, and you also being in your 20s, you're natural skin elasticity is still very high. Loose skin is generally made up of more water and pockets of fat - it tends to take a little longer to tighten up then just when you see the fat loss.
And just so the focus is in the correct place - "Abs are made in the kitchen" - its diet first, cardio and training second. IMO you don't need to worry about using GH.