The easiest way to do this is to purchase T5 strip lights and then install the Lutron Tu-wire ballasts into them and use with Lutron Tu-wire dimmer. It is a simple swap with the original ballasts. If you need to dim to 1% instead of 5% then go with Hi-Lume but this costs more.

Tu-wire dimming is starting to be more readily available from manufacturers. Juno and Cooper now offer it as an option in some recessed fixtures. Having fixtures built with dimming is usually a custom order otherwise and adds time and cost so doesn't work out much cheaper if at all than just swapping ballasts. Maybe you can Ebay or Craig list the original ballasts.

Tu-Wire seems to be the way residential targeted products are going from OEMs. Eco-10 is mostly commercial. Hi-Lume is both but at higher cost.

Here is a link that might be useful: Lutron Tu-wire

Thanks for the information--it sounds like a lot of people replace the ballasts in order to get the dimming. The Tu-wire looks good, but it's only for T4 and T8. In order to do T5, we did find one with an ECO-10 ballast at goodmart.com, so we're going to try that out.

Thanks for your help!

Advance Transformer's Mark 10 dimmable ballast can do T5/HO and works with Lutron Tu-wire controls.