Hay Rakes

Been shopping for hay rakes, looking for something that can roll 2 windrows together in one pass and would prefer something I can unhook and use as a single side rake 8 days out of 10 here in MT wouldn't need a side rake but would be nice to have available if needed.  I have looked at the vermeers, allens, new hollands.  I found some new holland and some deere rakes one throws left and one right.  My question is on the new holland rakes 258/260 (not many in our area) I have located some that are hydraulic drive and some that are ground driven.  I would prefer the ground drive so I can use it on smaller older tractors with little hyd. flow or none  (takes 8 gallons per minute according to dealer) the dealer tells me these rakes won't work well in heavy hay I need to buy hydraulic driven I have used old single side rakes when a kid to rake 9 foot windrows and if I remember right never had a problem could go as fast as you could hold on and you had to pay attention of course. How much faster would a hydraulic one be?    I am cutting 12-16 foot windrows.  Any thoughts are good.