Jeff,
I see no need for snaps...the weight alone keeps Deckadence in its place even towing at I-95 speeds (which is 62-64 MPH for me).
Deckadence comes in 6 foot widths, and even numbered lengths, for larger yachts they fuse the 6 foot widths together as needed.
We chose the 10 foot length for the interior, (as I recall, but I don't recall nearly as much as I did 40 years ago) since that would allow a v-berth to rear door walkway without a seam across it. That allowed the white carpet to cover the head, under the dinette, the helm and nav footrest areas without much left over, and required a little planning. Get some cheap clear 6mm plastic rolls as a template from Lowes as suggested by the installation pro on Performanceunderfoot.com.
For the cockpit we chose 6x8 foot, which does leave a 2-3 inch gap by the rear lazarette access doors, but saves $40 or so on the roll.
The throw rug we use for sand/water/dirt is very comfortable, washable or we just flap it overboard. Not needed with the Deckadence, which is very comfortable underfoot, but we just kept the throw since it was paid for.
http://www.amazon.com/gp/product/B00BT4 ... ge_o03_s00
One of the most useful items we've found for a TC255 is the folding rear boarding Flip n Lite 15270 stepladder we use instead of the Armstrong when on land, tie a Gear Tie around it and it can't fall backward, fits in the pickup bed, only 12 #, pic with 'custom boarding railing'. 300# ANSI rating for both of us and the dehumidifier too (but just barely). On the road, cushion the transom top with your throw rug and push it over into the cockpit or keep it in the pickup bed.
http://www.amazon.com/gp/product/B0043W ... detailpage
The Coleman Biscayne Big &Tall Warm weather sleeping bags zip together, fit the V-berth and are cheaper ($30) and store much better than hard to find 'California Queen' size sheets + throws or blankets (thanks and credit to Joyce and Tom Shulke on C-Otter).
http://www.amazon.com/gp/product/B00363 ... ge_o01_s01
Happy hunting! You'll love the boat.
John