I would choose the Pienza area over Chianti; I think it is more beautiful. Also, if you have time on your Pisa day you might be able to fit in a visit to Lucca which is quite lovely.

I think your plan sounds fine. If it were me, I would rent the car in Florence and drive south from there to your countryside base. I would probably not include Siena in favor of more time in the countryside of Tuscany. But if you want to visit Siena, your plan makes sense.

Congratulations! Please let us know the final plans..where will you be staying in Rome and for how long?

i have not found a place to stay at rome yet...most of accomodations seemed to be full...

any suggestions..?

Villa Dievole
Agritourismo Terrapille
Agriturismo Malafras

any feedback on the above ??

i am still trying to get replies from some pienza and montacino accomodations as recommended previously by u guys

Can't help with the above. If the above Tuscany hotels don't have openings try:

Montepulciano: http://www.albergoilmarzocco.it/hotel.en.php 90 Euro

http://www.laterrazzadimontepulciano.it/prezzi.htm 85 Euro

I've stayed at this hotel twice in Rome but I'm pretty sure they will be over what you want to pay. Great location and I've found them to be very pleasant and helpful..others not so lucky.
http://www.smeraldoroma.com/about.htm

We toured Dievole winery last year. Have not seen the rooms but the grounds and tasting room are spectacular.

Piazza Navona or the Fiori district would be a good base central base in Rome. There are a bunch of hotel recommendations on Slowtrav.com

alright...some updates

florence hotel for 2 nites booked..: grand tour

now for tuscany area which i am waiting for reply and debating on where to stay (siena/pienza or montalcino... sign!!)

we have decided to pick up car from florence /siena... drive to pisa on day 1 then go to accomodation at tuscany (whereever it is!) for 4 nites...

of coz now to arrange for car pick up location..

Lovely place just outside Pienza:
La Fonte agriturismo
http://www.lafonte.toscana.it/2006/ita/

Around 90 euros, double. The farm has a wonderful vista of the rolling Tuscan hills and villas. Lovely gardens. It's a working farm...very quiet (except for the hum of tractors working deep into the night. We loved watching them!). Apartments provide nice privacy. Daughter speaks english.

We stayed in the smallest apartment (Pagliaio) and were surprised at how much space we had. Very comfy large bed. Kitchen was nice but we only made coffee. They provide breakfast. Computer available. We also liked being able to park the car right outside our door.

Perfectly situated for driving around southern Tuscany: 5 min to Pienza, 10 min to San Quirico, 20 min to Montalcino.

Look up Stu Dudley's driving guide for this area. We were delighted with it.

Kokomi:

Are you saying you're going to p/up the car in FLR, drive to Pisa, then drive back to Tuscany all in one day?

I think that's awfully ambitious---and not worth it. Skip Pisa!

Here's an alternative suggestion (assume you're staying in southern Tuscany)---
drive south from Florence and visit the exquisite hill town, Monteriggioni (lunch). It's easy access from the autostrada. Have your camera ready as you near the town...the first glimpse of it is awesome!

OR, you could drive down through Asciano and visit the lovely Abbey of Monte Oliveto Maggiore (gorgeous terrace restaurant). The drive south from there to Pienza is simply amazing.