Patrick,
I'm not very familiar with Unique. However, SPF makes a very nice car, and I've only heard very good things about them.
"What's best" will really boil down to your personal preferences (as SPF and Unique owners will probably be a bit biased toward their own cars--and their responses to your question will likely reflect this).
You need to determine the criteria that are most important to you (e.g., similar to original, available options, cost), weigh the pros and cons of the two cars, and make the decision that is best for you. I would also recommend that you test drive both cars (if you haven't already done so).
You can find a great deal of information to support your decision on this site. However, be aware that you will likely get a wide array of answers to your question. Remember, opinions are like rear ends--everybody has one, and some of them stink.
Good luck.
Kevin