Looking for recommendation on installing a tankless water heater - any suggestions?

Do you want installion recopmmendations or brand recommendations? Rinnai is the only brand I have installed and it works great. Rinnai (http://www.rinnai.us/)

Looking for recommendation on manufactures?
How's the reliability?
Does it keep up on hot water demand?

Yes they do but there are other options such D'mand circulation systems or Watts systems. A good sized tankless system plus outside vent cao for gas or propane can run you $1300 while D'mand is cheaper and operates by circulating the hot water faster to you furthest faucet from the heater. http://www.gothotwater.com/D'MAND/tankless.asp What is your fuel source if you were to go tankless and how are your fuel prices?

We are using Natural Gas.
Currently the water heater is the only item running on gas.

Our kitchen is on the other side of the house from water heater (which is in the basement)
And it takes us several minutes to get hot water to the sink. And - will this help that issue or do I need to install a small water heater under the sink?

As of today, here, in California we deal with 4 major brands: Rinnai, Takagi, Noritz and Bosh. Rinnai is the absolute winner, Bosh is the absolute looser.

If your kitchen is far away, than Yes, you should install small, 6gln point-of-use hot water heater under your sink. Feed it with hot water into cold water inlet.

I would not install a tankless heatyer as a replacement to your existing system just to get faster hot water, it won't happen that way. In my opinion tankless are best placed in a space where you need a high volume of hot water and/or infrequent use. This way you can avoid using a 80 gallon tank just because you may have two or three showers or washers going at once. Its great for churches and schools where the demand may be high but very infrequent. Milo's small heater at the far sink may be your cheapest and best approach. I think the D'mand system runs upward of $300.

Good point: lots of people mistakenly believes that tankless water heater will give them "instant hot water". Not true. It will give you continuously hot water for as long as you need it.

Main advantage of tankless w/h is that it doesn't reheat 50 gln of water 24/7/365 and - of course - no open flame (pilot). It is only matter of time before tankless heaters will be installed in every house across America.

Milo is right and that day may come. Hope that level of demaqnd will bring the price down. My electric company gave me a 80 gal heater for $1 but the Rinnai tankless cost me $1300. The electric company saw us as suckers and we were, that heater is running my bill up about $75 per month. I also got thje government tax rebate of $300 just days before Uncle Sam cut that off.