|Well, tiptronic puts you in control of when gears are switched. On alot of automatic cars, there are usually only 4 gears and they are less sporty, due mainly because the transmission switches gears automatically from an economic standpoint (2000-3500 RPM's). With Tiptronic, you can hold out the RPM's longer for more speed and a sportier feel overall. Also, they tend to have an extra gear over automatic (5 gear tiptronic over 4 gear automatic). Tiptronics are by no means close to manual, and generally have a weaker transmission than manual, as well. They also don't generally respond to mods quite as well as a manual transmission.
A swap would not be made easier going from automatic to tiptronic, nor would it be worth it. I believe for the time, money and materials, it's better to either get it manual or tiptronic to begin with or just don't get it at all.