I just installed two SSD's in my 2012 MBP non-Retina and have been involved with some of the recent threads dealing with this issue.
The 2010 MBP is SATA-2 (SATA-II, SATA 3.0Gb/sec.). Newer models, if they have a SATA interface, are SATA-3. SATA-2 has a maximum of 300 MB/sec. If you can get mid-200's, that's pretty good. Still quite a bit faster than an HDD. The issue of SATA-2 vs. SATA-3 is important.
The OWC Data Doubler is available on Amazon UK and I presume other Amazon sites. I would use the idiom "built like a tank". I bought it - it's made out of metal and is very sturdy. I also see it's not cheap. You do not need the Data Doubler, similar brackets come up when you do the search on Amazon UK. Some people report that the cheaper brackets don't fit well. Also, there is a connector on the Data Doubler and some people have reported problems when they use cheaper brackets. I think the main problem is that they get SATA-2 speeds when their computer supports SATA-3. This may be less of an issue because you don't need SATA-3. If you don't get the Data Doubler, do some research to make sure people aren't having these issues. Maybe somebody here has a suggestion of a cheaper bracket.
The bracket is all that you would need to fit an SSD. For the 2010 MBP, I don't think it would make a difference where the SSD goes. (Of course you need tools - a Phillips #00 screwdriver; a spudger and a tweezer for the screws would be helpful.)
People have reported issues with the NVidia MCP79 SATA chips in this MBP and certain SSD's. To find out if the computer has this chip, press the Apple Logo in the left top corner, press "About This Mac", press "System Report", select "SATA" from the left dock under the Hardware heading. The name of the SATA chip should appear in the top middle portion of the window. If the MBP has the NVidia chip, you'll have to select an SSD that does not have problems with this chip. This involves some research on the web. There was a thread recently about a person who got a OCZ Trion for Christmas - unfortunately, it's one of the drives that don't work well with the NVidia chip.
In selecting an SSD, you can use a SATA-2 SSD, which should be cheaper than a SATA-3 SSD. However, I don't know if SATA-2 SSD's are commonly sold any more. Most SATA-3 SSD's claim compatibiity with SATA-2 but you're going to have to do research to see if people are actually using the SSD and getting SATA-2 speeds in the 2010 17" MBP (I think if it works in the 13" or 15", you're OK as well). Getting SATA-1 speed (half of SATA-2) in the MBP is a common problem with some SSD's.
The OWC videos are good - some other repair sites say that you need to disconnect these very small wire connectors in doing the SSD replacement and some people have broken them in doing so. The only cables you should have to disconnect from the logic board are the ribbon cables and the battery cable (optional, probably safer if you do disconnect it).
EDIT: Taking a quick look at the Amazon UK site, I don't see drives noticeably cheaper than the big name drives - Samsung, Crucial and SanDisk.