Here are some flights you can use to reach Tbilisi:
Frankfurt-Tbilisi, Air Georgia (with Boeing type airplane)
London-Tbilisi, British Airways
Zurich-Tbilisi, Swiss Air
Istanbul-Tbilisi, Turkish Airlines
Preferable currency (you can exchange at any place): US Dollars and
There are many private comfortable hotels in Tbilisi.
Costs of accomodation (single room, Bed & Breakfast): 50-70 US Dollars.
Guest House "Dzveli Ubani"