Does the tip not share the floorpan...
bit harsh coming from a panda owner.
yes the tipo is the original so coupe/tempra do share the same floor pan along with several others.
coilovers don't seem too popular on these cars, there's plenty of good set ups of springs/shocks which tbh will probably be cheaper than coilovers.
as for seats, the only ones that are a straight swap into a tipo are tipo/tempra/alfa 155/ lancia dedra.
155 seats would probably be the easiest/cheapest to get hold of, of the better style of seats, though whether they'll fit in colour wise might be interesting. i think they tend to be grey with red piping, though there's different styles available. but dedra leather seats are probably the nicest but also the hardest to get.
what colours are your interior?
oh forgot about the 3 door seats needing to tilt, that rules out most cars i'm afraid. but you might be able to get around it by stripping the seat down and reusing the frame with new the new foam and covers, but don't really know if that's possible. i think Coupe seats need a bit of work to fit? but they'll be about the only option for nicer seats other than 3 door sedicis.