Wine kits are about as easy as it gets. However, with those 7.5L reds I would definatley only do 5 gals or it will be way too thin. What I would do is ferment 5.5 gals. at first racking rack to a 6 gal carboy because step 3 (degassing with a fizz-X or mix stir) will be alot easier in the 6. However, when it is time to final rack to the carboy after adding the fining agent rack it to a 5, and whatever you do, do not top up at all with water. You should not have to top this up at all, but if you do use a like wine. Dont buy expensive wine for topping up though. I wouldnt have bought the 7.5 to do a red. I just did a 10L RJ Spagnols Petite Sirah and I am not happy with it at all at this point (just bottled Sat). It was way too thin made at 6 gallons. I added some heavy toast oak spirals and let them sit for about 5 weeks, but it didnt help all that much. The 7.5s are ok for some whites, but when wanting the bold reds like that use no less then a good 15L kit. Wine kits to me seem to be a "you get what you pay for" situation.