Touring - Medium Seat pack for light touring: Suggestions?

I'm sure this has been kicked around, but it's worth another query as we get close to spring here in Wisconsin.

I'll be doing some light "credit card" touring and road riding on a new bike. The Felt does not have braze-ons to mount a rear rack (which is my usual M.O.) Of course I won't be doing the fully loaded touring I did in my youth, but... I kinda like having somewhere to put an extra shirt/sweatshirt, plus misc repair gear, snacks, etc. I won't always be wearing a 3-pocket jersey.

Am I best to stay away from seat-post mounted racks? Will they just be trouble, swinging about in the long run?
I'm looking at the

Trek Quick Cleat MOunting rack (http://willybikes.com/site/itemdetails.cfm?ID=5290&Catalog=1&sort=Price)
or a
Jannd Bag (http://www.jandd.com/detail.asp?PRODUCT_ID=FMW2B)

any other ideas? The Carrandice look nice but a bit pricey for my taste right now

I've been looking at the Carradice bags, and associated 'bagman' racks that attach to the seat rails for commuting and credit card touring. The Nelson longflap looks like one I'd like to get. You are right that the price is a little steep, but I understand the quality is top notch.

The problem is that there are no retailers of these products here in Canada, and I'm a touchy feely kinda guy when it comes to bike luggage.

**Edit** You might consider a handlebar bag instead. Arkel makes good ones, but they are pricey. MEC has the Serratus bags. I don't have a handlebar bag, but my Serratus panniers are about 15 years old and still work great.

The problem is that there are no retailers of these products here in Canada, and I'm a touchy feely kinda guy when it come to bike luggae.

agreed
I'd like to see how they look... Carradice are quality if not sexy

I have two Carradice bags, the Pendle and the Camper Longflap. Both are excellent quality, sturdy material, and are great to use. I use mine with the SQR adapter so I can quickly install and remove the bags.

I have no experience with Bagman packs, but they appear to be on par with Carradice. I use my bags a lot. They are great for carrying clothes and things for commuting, and work well for shopping. For a credit card tour, I would lean toward the larger bags depending on how light you like to travel.

Some additional choices here:

http://www.rivbike.com/webalog/baggage_racks/

This SQR looks promising -- I'd like something larger than one of those underseat spare tube bags
But at $120 bucks from the us distributor, that is a bit of change