PayPal is a good medium for transactions..but only because it's popular. I've had bad experiences with PayPal personally, but it's good because many people that shop on eBay use it, and it's quite versatile. You can use their e-cheques too, don't know what it is/how you do it, but it's pretty safe.
They enjoy screwing you over though, especially if your account is fairly new and suddenly has a large amount of ingoing/outgoing transactions. This was what happened to me when I sold some virtual items (in an MMORPG) and received $800 USD. My account was fairly new, too (created it just for the purpose of receiving money for the aforementioned items), so they decided to "limit access" to my account. I had that $800 in my balance, but I couldn't withdraw it to my bank account.

I emailed them, then called them up, and got redirected to the Singapore branch. Spoke to some Chinese lady who could hardly speak proper English to me, and she said she would have to confirm with my buyers whether I delivered the items, because I was unable to provide tracking numbers/invoices for the payments (of course, they're virtual items..what is there to ship?

). She said she would have to contact the buyers by email and ask them.
No problem. 6 days later, still no response. My buyers denied receiving any emails from PayPal either. I called the US branch this time. They were MUCH more helpful. The lady I spoke to told me to wait another 2 days, and if none of my buyers filed a dispute, they would remove the limitation.
True enough, they did. Haven't had a problem thus far.
That experience has made me dislike PayPal, though. But since it's so widely used, I have no choice but to stick with it. Sure, the problem was solved -- but it was a waste of a week of my time. Time that cannot be recovered.
A tip is to ask your buyer (if you're selling) to select the option "Personal Payment - Others" when making the payment. Don't select "Purchase of goods" or anything like that, because PayPal actually charges you for the transaction (forgot how many %). Only exception to this is if you use eBay, then you should use the default. This way you get buyer-seller protection should anything go awry.
Another alternative, I'm guessing, is to use Western Union. I don't really know what it's about since I've never used it, but it's another alternative you could consider.
As for shipping, I wouldn't know. I haven't shipped anything internationally yet, but I think PosLaju or any other courier company (FedEx, DHL, etc.) will do.