Replacing the Keyboard
It would be fairly straightforward to switch over the keyboard from your faulty T61p (15.4" WS) with the replacement T61 (14.1" WS) to support your keyboard language requirements - if you want I can post in a link to the official Lenovo Hardware Maintenance Manual for you (your TP is a CTO based on Product ID 7661-YEF), so you have a guide to refer to but also there's the Lenovo Service Videos as well (I'll need to hunt out the link for that as well).
CPU Upgrade
My tuppence worth would be to upgrade the CPU to an Intel C2D T9300 but saying that it all depends completely upon what your going to be running on your TP - the working T61 comes with a T8100 CPU (I installed that previously), which is still decent CPU IMHO especially for day-to-day work but saying that you also have the T7700 CPU in the faulty T61p...both CPUs have pro's and con's. Again the Lenovo Hardware Maintenance Manual & Service Videos are ideal steps to follow on how to do the CPU replacement if you go for it...it looks difficult but it is actually a very straightforward process but if you take your time, document which screws go where, use a decent thermal paste cleaner and a decent thermal paste (Artic Silver 5 is the bee's knees!) you'll get there in end.
Bear in mind that if you do install an SSD into your T61 that will provide a good performance increase as well, as it will make the TP a lot more snappier in the OS - I see that with the T61, X61, R500 TPs that are my main machines that I work off of.
SSD Upgrade
The ones I personally stick to are the Crucial M4 SSD Series but I use the 256GB models - I have used Kingston SSDs in the past but I have had occasional problems were the onboard SATA Controller wouldn't pick-up the SSD during POST...of course this was older models, plus Kingston have released updated firmware which has improved performance; a mate of mine swears by them for his X60 and X61s TPs.
From the three you've listed (links below) I would suggest considering the Crucial M4 SSD...it's an older model BUT they are pretty reliable (that's just my tuppence worth! lol) and I've had decent support from Crucial, in terms of a replacement (only had the one die on me, knock on wood!) and firmware updates, also you get a few more gigabytes worth of storage - the SanDisk SSD is decent enough but I'm not to keen on OCZ SSDs, as I personally have had a few duds (a pain to get replacements) and also friends, family & previous co-workers have had the same as well...although saying that new firmware releases have addressed some issues.
Forgot to mention remember your TP has the Middleton BIOS installed, so you'll get native SATA-300 speeds for the SATA Controller.
SanDisk SDSSDX-120G-G25 120GB Extreme SATA III 6Gb/s 2.5in Internal Solid State Drive: Amazon.co.uk: Computers & Accessories
Crucial CT128M4SSD2 128GB M4 SSD: Amazon.co.uk: Computers & Accessories
OCZ AGT3-25SAT3-120G Agility 3 120GB SATA III 2.5 inch SSD: Amazon.co.uk: Computers & Accessories
Bear in mind as well that you can easily purchase a cheap 2nd HDD Caddy as well, so you can re-use the HDD in the Ultrabay (Slim) to give you more internal disk storage or look at external storage solutions.
I hope that's of some help to you but also I'm sure other members will also post in their respective comments and input as well.
Cheers, SB
EDIT: Forgot to ask do you have a budget in mind for the upgrades?






