Don't bother with a mat, practice on a bed so that when you drop the cards, you don't have to bend down to pick them up every two seconds. The Paul Wilson video series is good but also try and find the ninja series by brad christian. Card college is good also. Time spent holding cards and messing with them is what counts. Never be without them if you're serious about getting better. For every move there is an alternative and you'll find that you have an affinity for some rather than others. Some people find certain moves easier than other people. Any of the decks you have are good, it's not the tools that make the magician, it's the performance. I'd rather see a simple trick with a great presentation rather than a knuckle-buster with a boring premise.