Spindle length for new chainset

[Piedwagtail]

Hi everyone,
I'm considering replacing my entire drive train, however I have very little money so need to do it on the cheap.

Its currently set up with;
Chainset of unknown origin (though the other original parts were Sachs-Huret)
Sachs-Huret front deraileur
Shimano 600 6 speed freewheel 14-32
SIS 6 speed deraileur
5/6/7 speed chain from Halfords
Sachs-Huret friction shifters

All of this would be replaced with;
Shimano FC-2350 Compact chainset
Cheapest Shimano FD I can find
Generic Shimano 6 speed freewheel 14-28
Cheap new Shimano RD
Another of the same chain
Same shifters

Most of this should be fine as far as I know, I'm pretty competent with stripping everything down and putting it back together.

My problem my lack of knowledge with chainsets.
I have a old Peugeot which I suspect has non-standard threading, so I don't think I'll be able to add a cartridge BB to the shopping list.
So heres the actual question, will the new chainset fit on the old spindle??

It has a stamp in the center saying 123, which I assume is length??
I've also looked on Sheldon Brown's website and found its a JIS taper.

Also will a new spindle be easy enough to obtain if necessary??

I hope I've supplied enough info (worried theres a bit too much, sorry)
Thanks in advance for any replies
and then more thanks for taking some time to read this

[trevgbb]

As you suspect, you main problem will be the BB axle length, unless you are replacing like for like on the chainsets, you may need to try several axle lengths until you get a good chain line, as not all chain sets fit the same;
see these pics I posted to a previous Q
http://forums.bikeride.com/thread-2024-post-10256.html#pid10256
your local LBS should be able to help, especially if you are buying from them.

[Piedwagtail]

Thanks for the reply.
Exactly the opposite of what I wanted to hear, but I was pretty sure it was the reply I'd get
The local LBS is rather rubbish, so I'll have to take a trip a bit further afield for some proper selection of parts and specific recommendations.
No problem though, any excuse for a ride!

Hopefully should have money together to get it all done in a month or so all being well.
Thanks again