Advice on first Oud

Syrian ouds sound really quite superb on the whole, with a very clean tone, however I would be mindful to take into account the individual instrument when you are making your decision.

If you have your heart set on a Syrian oud (and I entirely understand why, one day I shall add one to my collection), then a truely beautiful Turkish oud turns up, I would still give it a play and see what you think.
As with all hand made instruments, the variation between each one can be huge. My Turkish oud has a very big body, and projects much more like an Egyptian oud than a Turkish one, albeit in the higher tuning.

If you are buying second hand, it's helpful to know a little about how the oud was looked after in the past, although usually you can tell this by talking to the seller.

Floating bridges on a fretted instrument are incredibly useful for intonating the frets correctly, although this isn't so necessary on an fretless instrument. Ideally, the octave should be played at the point above where the neck joins the body, and you might find that an instrument with a floating bridge is intonated closer to this point than a fixed bridge just because it's slightly easier to adjust once it's built.

With the lack of overtones, I think that is more down to the smaller body size of the ouds commonly used with floating bridges.
As a general rule, larger bodies will resonate more, and produce more overtones, regardless of the type of bridge, although the bracing on the soundboard will shape these overtones (often in a very particular way designed by the builder).
I've seen a number of Egyptian ouds with floating bridges, and these produced some incredibly rich overtones in the lower register, which sounded really quite incredible.

As for Bahadir Sandi, I have wanted one of his Father's ouds for a good few years now as Saadettin Sandi does produce some truely wonderful instruments. I did know a chap who had one, although sadly I never had a chance to play it.

For what its worth, I think you are going about this the right way in thinking about what qualities you want in your first oud before buying.
My first oud was a pretty ordinary Turkish tourist oud, which took an age to tune and didn't have much sustain.
My current oud in comparison is a much high quality instrument, holds its tuning very nicely, and is infinately more enjoyable to play so I actually practice!

I hope in some way that this rambling answer has helped, but at the very least I wish you luck with your search.
Be warned though, the oud is very addictive, and you may find yourself losing hours when you start to play.

It's certainly worth it, just remember to make time to eat

Thanks for your reply and advice oudalally!

I'm planning to buy new and I want to get a high quality instrument to begin with that's going to last a long time. I've never been in that concept of buy a cheap one for beginning and then upgrade later. Buy one and have it last right through. I would really like the opportunity to go oud shopping in person, but unfortunately oud's not popular here in my country, so I have to buy online from overseas, hence why I'm trying to find what I want ahead of time

What's your opinion on woods? There are 3 models I'm currently looking at:

Soundboard - Spruce
Body - Mahogany

Soundboard - Spruce
Body - Venge, Maple, Walnut and Paduk

Soundboard - Spruce
Body - Mahogany and walnut

Is there going to be a big tone difference between them? Do some have higher and darker tones?

Thanks!