Looks like you're saying that you'll order tubular tires and are planning to get (700c, not 27") clincher wheels and tires at some point.

Might be a good idea to bring one or both wheels with you to the store, to ensure that they order the correct tires.

In addition to ordering at least three tubular tires (including a spare), order tubular glue too, since very few bike shops stock it.

Tubular tires are available in a wide price range, from training-weight tires at around $40 to a couple of hundred bucks.

The cheap ones are heavy and will probably look a bit crooked after you glue them on the rim.

The more expensive tubulars are hand-assembled and usually go on the rim pretty straight.

They're also the tires people have in mind when they talk about the "magic" ride of tubulars. Inexpensive tubulars ride no better than clinchers in my experience.

While you're waiting for the tires to arrive, watch some videos that detail the gluing procedure.

In case the videos don't mention these tips:

---Before you pick up the tires, have the bike shop inflate the tires to about 3/4 of full pressure (e.g., to 70 psi or so) to check whether they leak.

---Leave them inflated at that pressure for 24 hours or so at home, to check for slow leaks. Best to do that off the rims; distributors won't take back leaky tubular tires under warranty if they have any rim glue on them.

(Note: you'll probably buy inexpensive tubulars with butyl tubes sewn in the tires, but if you buy the more expensive tubulars, they might have latex tubes, which lose pressure faster than butyl.)

---If the tires hold air, stretch them onto the rims (hope you have strong hands and/or the videos offer tips about installing the tires) and follow the video instructions for gluing.

You'll probably get various opinions about which glue is best, whether to use solvent to remove the old glue before applying the new, how much glue is needed, how long to let the glue set. etc. For your first tubular installations, I'd err on the side of caution.