http://www.tomshardware.com/forum/353572-31-build-upgrade-advice - fill in as much as you can
There is a tremendous resource here at Tom's of enthusiast builders. All they need
is a clue about what the OP (original poster) needs and has a budget for. Sometimes
what you can get for your money far exceeds your expectations when they come up
with options that would never occur to you because of the confusing array of information
on the web and through advertising.
Your country of origin, where you can order from, what your technical skill level is are
just as important as your budget and use for the computer.
The standard way to express what you want is to fill out the pcpartpicker.com for for
a build to feel your way around spec'ing a system out. If amazon or newegg are not
available then there are still lots of options.
To finally answer your question about old i5 to new i5 the answer is, it depends. The older
i5 system has many many options and lots of solutions exist for almost any need and
budget. You get tried and tested solutions often with a budget path for everything.
The new i5 on the other hand has the new technologies built into the motherboard and
things like M.2 with NVMe technology as well as DDR4 for a little more stretch to the future.