If £1k is your budget then you'll find many good rigs in the for sale section on here.
There's a good selection of amps (including a Markbass Rocker), & for cabs there's an Acme B2 & a Markbass 6x10 to start with. And you'd still have change left.
If you went down the combo route, there's a Markbass 2x10 for just £550! & if you needed further, there's a few matching 2x10s, again all below budget.
The last thing I would do is spend money on your old cabs (no offence intended), but reconing an old peavey is gonna cost more than it's worth.