Hi Amanda,
Before making a decision you have to think about a couple of things
You can get purpose bred hybrids which are prolific layers (ISA browns/warrens will lay around 300 eggs a year for the first 18 months or so then production drops off rapidly; so you either cull, replace, or keep as retirees) but are no good for meat.
You can get pure bred hens which are quite good layers, but not as prolific as hybrids (leghorns lay large white eggs, but are known to be flighty; Rhode Island Reds (RIRs) are good layers of brown eggs etc) which may be good for meat.
You can get dual purpose chickens, in which traditionally boys have been reared for the table and the girls are kept to lay eggs, Sussex and Ixworth are traditional english dual purpose, Faverolles are a traditional French dual purpose which are becoming more common in the UK.
Then you get specifically bred meat hybrids; produced by large hatcheries, they are "designed" to lay down muscle much more quickly than either the parents or other breeds. Generally they are divided into "fast growth" (Ross Cobbs, table weight in 8-10 weeks), and "slow growth" (many of the Hubbard/Sasso lines, table weight in 10-16 weeks). Of course you can leave them to grow a but longer, but especially with fast growers you are risking leg problems and heart problems as they get heavier. With the medium, or slow growth birds this isn't so much of a problem - especially if you keep them on a lower protein diet. This year I dispatched my last two at 19 weeks and they were as tender as the ones I dispatched at 12 weeks.
Now, one of the "problems" with dual purpose birds, is that they are slow growing, and the boys may not be table ready until 26 or more weeks, usually by which time they have been crowing for weeks; if this would be a problem for you or your neighbours, then meat hybrids would probably be the way to go, as they are usually ready for slaughter before first crow (or if it's more than 12 weekd for medium/slow growers, you can slaughter AT first crow).
Happy decisions