Hi Rumba
I would agree with the sentiments expressed above - Litronic (Xenon headlamps) are very useful, as is PCM/Sat/Nav (this may be upgradeable to PCM2 with greater detail, MP3 CD playability and TCM - might be worth asking about this, and see other threads on TCM/Sat-Nav in the Boxster & 997 forums) . I personally wouldn't be bothered about the integrated GSM phone, but just depends on how contactable you need to be.
I like the full leather option, IMHO it gives a certain extra sense of occasion to the interior, and heated seats are a must for me. With dark colour interiors some of the Aluminium/Arctic silver trim packs can look effective. I had a small arctic silver trim pack on my old 986S and it went well with the black interior - a question of personal taste in essence.
Although the BOSE sound system is very good, the optional Porsche Sound Pack isn't too far off the mark, with good volume and bass but the standard sound system is rather feeble in my opinion.
Reversing park sensors are also handy, but can look rather prominent on some earlier models, so it's a question of taste really - I quite appreciate mine when squeezing into tight places.
Full electric seats with lumbar support and memory can also be handy, especially if another driver uses the car from time to time.
I hope this is of use and have fun looking for your dream car!
Rob[8D]