Did you not make it over the border to get hands on time with some pistols?
The conversion kit is not a bad way to go, but neither is a dedicated 22 pistol. As was said, any trigger time is beneficial, so using the same frame and trigger is not a necessity, just a extra nicety.
Remember that using the conversion kit limits your options should you choose to get a lower power hammer spring. A #15 is reliable with centerfire, but #17 or #18 is needed to reliably fire 22. (stock is #22, so a #18 is still a big improvement to trigger pull)
Also remember that 22lr is not very powerful... so a polymer frame isn't a bad thing. Personal preference is always the decider though.
The MKIII is a good option and is metal framed... the 22/45 is a MKIII with a different lower frame... Polymer but shaped like a 1911 frame.
I have the SR22 and find it an excellent 22 pistol. Put 450rds though it this weekend.
For me... I just like having more firearms and a dedicated pistol means more in my collection.