I'm going to suggest the bigger tire at least on the back. Use whichever matches the shape of your rim up front...if there's any doubt, use the larger tire up there, too.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

at 190, you should be fine with 19mm tubulars. I used conti comp tub 19s when I was 180, without incident. Actually, I didn't have a choice, at the time I had a P2, a 22mm tire wouldn't fit between the chainstays, which was one of the 3 reasons I sold it.

A 22mm tubie will handle a little better, but either should work. Just make sure you keep the tire pressure up.

Here's what lennard zinn has to say...

From Inside Triathlon web site

http://www.insidetri.com/...articles/2040.0.html

How wide is too wide
Dear Lennard,
I'm a light rider who has always used high-pressure 20mm wide clinchers for training due to their low rotating mass and rolling resistance, However, I'm finding that it is becoming increasingly difficult to find anything but 23mm tires. A local bike shop salesman told me that this is due to the current thinking that a 23mm profile and lower pressures (I usually run 140psi) actually result in lower rolling resistance. I've heard similar comments before, possibly even in your column. Is this true?

It seems counter-intuitive; I would think that with a given tire construction and pressure, a wider cross-section would simply mean a wider contact patch, which should determine rolling resistance. Similarly, I would think that with a given tire construction and size, a lower pressure would mean a larger contact patch, and, therefore, increased rolling resistance. Extrapolating the "wider and softer is better" logic, we should be seeing Lance in the Tour riding balloon tires pumped up to 20psi. Am I missing something or is this a fashion trend?
Langley

Dear Langley,
It entirely depends on the road surface. If it is chip sealed and you ride with a 19mm tire at 140psi, there is no question that you will have higher rolling resistance than with a 23mm pumped to 90psi (assuming that both are high quality high-thread-count tires). Every time you deflect the bike and rider up and back, it costs you energy, as opposed to absorbing the gravel hunks into your tire. This is the same reason that suspension makes a mountain bike, car or motorcycle faster on rough terrain. If you are riding on a smooth track, by all means use a 19mm tire and pump it up to super-high pressure.
Lennard