Hmmmm... I haven't tried the Rod's chaps. You could always order them and see how you like them, and then send them back if they don't work. It is difficult to get quality materials and proper fit off-the-rack, but I think Hobby Horse is an exception.
I totally understand showing on a budget. However, your chaps and your hat are the two pieces in your show wardrobe that deserve the greatest amount of money. Your chaps cover half your body and can last you for YEARS (my tan ones are 13 yrs. old), so making the investment in a quality pair will save you money in the long run. I'm not saying everyone must have custom-made chaps, but don't scrimp when it comes to quality and fit.
You may have better luck finding good quality chaps (either customs or Hobby Horse) used on ebay or the forums at www.pleasurehorse.com (there is a link to the forum on the top right). Just be sure you know your measurements, and maybe find someone locally who could make minor alterations to get that perfect fit!