Republic of Georgia and Moldova

I expect that you'll have to fly between countries and you can do that for about $150 US. Try www.skyscanner.com. You'll also be more likely to find info for these countries through www.lonelyplanet.com - their forum and their guidebooks.

I cant imagine going overland unless you have a week t spare. Pretty tough trip with some pretty tough borders and visa requirements between the two. Flying is the way to go, but the one $150 flight I spotted at random was 14 hours on Aeroflot with a layover in Moscow I think. I have an issue with supporting anything Russian right now, but I bet you could come close to the same price and see some more of the world if you purchased a couple of individual routes. Say Chișinău to Kiev or to Istanbul and then after a few days a second flight to Tbilisi.

I like Google Fights and their interactive map https://www.google.com/flights/#search;f=KIV;t=TBS;d=2016-05-31;r=2016-06-04;tt=o

I can tell you a little about travel in Moldova. We were just in Chisinau for 2 nights at the beginning of this week. We took the night train from Transylvania to Iasi and then a mini bus from Iasi to Chisinau. There are many mini buses and some full-sized buses in Moldova. They seem to all have placards in the front window to advertise where they are going. We hung out in the capital while we were there, so I cannot speak to moving around the country. When we left we took the night train to Bucharest, which also made several local stops on the way out of Moldova. Checking the train schedule at the station may be the easiest way to see where you can get by train.
The people were friendly and many spoke English. A much higher percentage of people than in Romania, in our experience, so that was helpful. The food and wine in Chisinau is cheap and so, so good. Be aware that public bathrooms (like at the park or at the border) are squatty potties and cost around 2 leu to use. Have a great trip!

I was on a guided tour of Georgia for a week about 4 years ago. Outside of Tbilisi, English was almost completely unknown. Russian is the second language there. Signs are in Georgian, which has its own alphabet, unrelated to any other. Road conditions were pretty bad (the main "highway" linking Iran and Russia had huge potholes) and the drivers are a little crazy. Are you planning to use a local guide/driver? It's a beautiful country with great food.