Switching from hard drive to SSD???

So I was cruising the net looking at hard drives, because I was a little worried that my next laptop won't have enough space for me. I came across SSD's. I did some more searching on how they work and how they are installed and I am rather curious about getting one and it's performance.

My questions below for those who are nice enough to help me.

I have a Toshiba Satellite and will likely soon get an HP EliteBook 8730w. Based on my internet search, they both take a (2.5in Sata II), did I get that right, is that all the info I need to take into consideration for hardware compatibility?

Can I move the SSD from my old laptop to my new one? If I can, then will I have to wipe the SSD clean and start over in order for the switch to work?

I worked it out that I only need to use 60.1GB of space, and from there I will use my external hard drive for back up. I am getting the 90gb, and doubt I will ever exceed 70gb, Is that cutting it too close? Personal question I know, I just didn't know if there is any obvious reasons why it would be a stupid idea.

Will watching download videos off of my external hard drive kill it faster than they normally live? Do external HDD's have heat issues?

This is the one I think will suit me. Does anyone have any issues with this company/product?

http://www.newegg.com/Product/Product.aspx?Item=N82E16820227608

Edit: Is there free copying software that will allow me to copy my hard drive over to my SSD so I don't need to buy a new OS or anything?

 

OCZ are a great company and should be trusted in this area.

However, my personal recommendation at this stage is to avoid SSDs as in my personal opinion the technological advances so far have not been enough to justify the use of an SSD as an only drive in a system.

Also, 80GB is, in my opinion, easy to fill up these days. I would recommend sticking with the hard drive supplied in the laptop, and I would recommend getting one with at last 250GB of space. Keeping your data in multiple places is the best way of preventing it's loss.

If you do decide to go ahead with this, programs such as Acronis True Image Home or http://majorgeeks.com/DriveWizard_d799.html would accomplish this.

Please note neither of the above programs are free, but I am not aware of any free programs myself and I would be hesitant to recommend a program that I have not used.