Are you doing free motion, or straight lines? I find straight line quilting much easier on a domestic machine. Rolling the excess quilt works well for straight lines, but pleating or "puddling" it works better for free motion.
I think the 301 will be a good machine to work on, but you will find it easier if you leave it in its cabinet. As Cari says, it's much easier to quilt if you have a level workspace. You can place a card table, ironing board, tv tray, etc. strategically around it to support the extra parts of the quilt. Don't move the machine to counterbalance the weight of the quilt; just put supports in place, and bunch up the parts that aren't currently under the needle so that they aren't pulling on the working part.
A suspension system would certainly help, but isn't a necessity. I don't have one, but used a friend's and it was great! I have quilted a couple queen-sized quilts on a normal little domestic machine, and it's certainly doable.
You seem to be on the right track. I suggest working for short periods of time, taking lots of breaks (wrestling this quilt will give you a shoulder workout!). And remember, done is better than perfect. Keep plugging away, and you should have it done well before Easter!