A total newbie asks for help

Hello there rec.ponders:

I am a not-so-handy man who has promised a simple backyard pond to his
girlfriend for her birthday and, upon doing more research, is feeling a
bit over his head. Our backyard is quite small and mostly paved with
brick -- more a courtyard, really. Right now we have a raised
rectangular herb garden in the middle, approximately 2 feet by 5 feet,
with brick walls; our goal was to replace this with a rectangular raised
pond of roughly similar dimensions. We want the bottom of the pond to
go about 2 feet below the ground level, with lip of the pond to be about
18 inches off the ground,and wide enough to sit on, and to make a mosiac
on the outside wall of the pond. This seems like it should be a simple
matter, but in fact we are getting quickly overwhelmed as we try to plan
things.

From some books I've been able to read, it seems that the simplest
strategy would be to use a preformed fiberglass liner. As near as I can
tell, with a such liner, we could dig a hole, level the bottom, drop in
the liner, and then backfill it into place, and it would be rigid enough
to support itself partially above ground. The problem is that most
liners I've been able to find are much too large, and are in natural
pond shapes rather than a simple rectangle. The other option would seem
to be building up with concrete blocks and then lining with a flexible
liner, but the book we have on the subject says that we'd need to create
a poured concrete foundation for the blocks -- a task that is much more
ambitious than anything we've ever undertaken.

So, I guess my questions a Would it be possible to use a preformed
fiberglass liner as I described above to create a partially aboveground
pond? And what are reputable vendors of such liners? If I go the
concrete block route, do I really need the poured concrete foundation?
I'm sure I'll have follow-on questions but I suppose these are the ones
to start with. This total neophyte thanks any helpful posters in
advance. Oh, I should add that I am in Baltimore, MD, USA -- not a
terrifically harsh climate, but it does snow and freeze during the winter.

Thanks again
jf