Pentax Vs. Canon EF

[yommytacoe]

I just purchased a used Letus Extreme that came with a Nikon mount. I have a huge variety of lenses, including Nikon, Canon, and Pentax that my parents and I have collected over the years. I already have a canon FD > EF converter, so I can use my FD lenses on my 40D, but for the Letus, I can't decide which additional mount to get; Pentax or Canon EF. My initial idea was to get the EF mount, and just buy an Pentax K >EF Converter, but I'm not sure if that would cause vingetting or distortion with the adapter. I don't feel like spending 200 dollars to get both mounts.

What's the best option?

If it makes a difference, here are the canon/pentax lenses i have.

Pentax 35mm f/2.8
Pentax 50mm f/2.0
Pentax 35-135 f/3.5-5.6

Canon 17-85 f/4-5.6
Canon 50mm f1.4

Thanks for the advice!