Excellent question OP,
and thanks for posting - it is likely that SWMini pieces will accrue some value, and some of the WotC han's went for some decent moneys back in the day (Han Scoundrel, Han Hero of Endor etc).
Imperial Assault is also releasing a Han figure, which will be in heroic 30mm scale, and thus a little larger but compatible with SWMinis.
I'd have to echo Echo24,
and say, so long as you have the right stat card, thats the main thing.
Everybody wants to be 'reading from the same songsheet' in a tournament setting.
You also want the play-token to represent the figure as best as possible.
At an official tournament locally in 2009, a piece was stolen during tournament - and it was permissible for the player to play (and go on to win) using only a folded postit note reading 'Chewbacca" as the square token hehe.
I'd say, unless the tournament is not one in which you'd want to partake anyways, you'll be alright to use printed cards and 2Dtokens.
Luckily, there are better options than manually resizing images in GIMP/Paint, or using a postit note
pepakura (papercraft) tokens that you'll find in the
"Custom Minis FAQ" thread of the Custom Forum - if they're still there, I think yours truly linked to them there.
There's also google search hehehe.
2D tokens are part of the proud tradition of making custom miniatures...
You can print out the tokens,
and then use a smart-strip or coin, washer, bottlecap etc... to attach the token to a base of 'legal size'.
At this point, I also recommend scotchguard, because pepakura/papercraft models are hydrophobic (they are watermagnets, and get soggy when wet).
If you're feeling more adventurous,
there are aliens and vehicle pepakura/papercraft that you can make too - the LAAT/i or LAAT/C gunship is difficult to make hehe.
The vulture droids or hailfire droids are also difficult to make. The Spider Homing Droid, less so.
If people let people use 3D custom figures or postit notes in tournaments,
I'm sure it'd be fine to bring some 2D tokens to a tournament.
Happy days,
and hopefully you're able to find an agreement to play,
either in tournament, or in your local game store/club for fun.
Thats the main thing -fun- who cares what the minis are really
(and worse case, there's always vassal online)