Here are some forms to use as a guide to measuring your rig for the sails you need. Once you have these measurements you can compare them to other similar boats to judge their suitability.
FX Sails - Non-Furling Headsail Measurement
FX Sails - Mainsail Measurement
To compare rig dimensions with other similar boats, look for the following codes:
J = distance from headstay at deck to mast
I = distance from deck to max hoist/forestay tang on mast
P = distance from boom to max hoist of mainsail on mast
E = length of foot of sail along boom.
Here's a link to a good database of this data.. you won't likely find your boat here, but you can check for comparables once you've got your own measurements.
Those little bilge keelers are solid boats, not great performers but might be a good starter. Very popular in Europe where many harbours dry out regularly..