Diane, Can I also play Devils Advocate here please???
Now I do not know your sewing experience as you have just joined our lovely forum, but if your Dresden Plate block shows your level of skill I would say you are quite accomplished.
I also do not know how much P&Q you have tried or achieved before, but again that one block was very nicely done indeed.
You are setting off on your journey into the Dark Side with a pretty humungous project...ie a double (or was it King size ?) Memory Quilt ... not just a quilt of a certain block or pattern.
Not just a sampler quilt but something you have to seriously work out and consider, a one off!
Yes, With a quilt that size (unless you delve into the underbelly of the Dark Side ie QAYG) the largest Harp space possible would be a bonus, nay is a necessity,
but
before you go and splash the cash...
try a smaller project... a wall hanging, bag, lap quilt or similar.
Practice your piecing, try WF quilting ( and the Devils own, FMQ if you insist .... shudder!! ...)
to make
absolutely sure you love this Dark art ...
It would be heart breaking if you bought the spankiest machine around only to find in a month or twos time that it really isn't your cup of tea !!!