HMG + HCG. You don't have to come off for it to work.
hMG actually contains hCG, as well as actual LH (which is what hCG mimics in the body [read my sticky on hCG if you haven't]) and FSH. Anyway, either or (or both if you want as Van suggested) will work, hMG is going to be harder to get on the black market (Not that I ever condone black market purchases but I'm being realistic) but will work a little better. Both will up the sperm count via restarting the HPTA between the HP and TA. That is, to mimic LH (Luteintizing Hormone) from the Pituitary for hCG, and for hMG it also contains FSH (Follicle Stimulating Hormone) again from the pituitary, both working to aid in the restart of the body's process of spermatogenesis.
As far as PARAVOL goes, I have to admit I don't know anything about it, I googled it and it appears to be a natural/holistic way to "up your sperm count for only 24.95!" The first item listed on the ingredients is "Horny Goat Weed". I mean, if it makes goat's horny it should work for you too right! (Yes, I know that isn't what it means for the neverending supply of jack asses trying to desperately to disprove me on every post).