MTB to roadish conversions are a lot of fun to build and can make great allarounders. I have built a number over the years, including one I hauled on top of my Land Cruiser for a summer adventure across the country to the Outer Banks. With 1.5" slicks, the speed penalty is small -- <5% -- when compared to a steel road bike.

The key, as noted above, is tinkering with the fit. MTB's tend to have longer top tubes, sometimes requiring a taller and shorter stem. Also, MTB stems will not handle the diameter of a road bike bar (although sometimes you can spread them. The Ritchey looks like a good base for a conversion. I suggest you start with the original stem, see if you can squeeze a drop bar in there. If so, check out the fit. If need be, you can go with a shorter stem. A better option is to get an adapter and play with different threadless stem options. If still too long, go with a no setback seat post. Niagara has the Origin 8 for about $25.

BTW, I would suggest Panaracer Urban Max tires in 1.25". Bullet proof, sufficiently roadie and should be able to swim through a mile of loose gravel.

For fun do some searches on this forum for conversions and gravel grinders.

Also, both MTBR.com and retrobike.co.uk/ have great MTB dropbar threads.

Here are the two I presently have on hand. I will build more. Lots of fun. Let us know how it goes.