I've posted pics of my collection along with other sporran related items and here's my haypenny's worth of opinion:

Go with an L&M from any of the suggested dealers (USAK, Scottish Tartans Museum, and Stillwater) since they only selll through their dealers. You might forget the seal sporrans if you read my post on importing seal sporrans to the US. Bit of politics, but the short answer is that most Canadian sporrans are made with fur seal causing an importaion headache.

One advantage to L&M is that you can look at how your custom sporran will look on a tartan. find one as close to your clergy tartan as possible.

I have 25+ sporrans and the L&M build your sporran tool is a serious temptation.

Lead me not into temptation...