rear mechs will work (assuming you don't mixe 7/8spd rear mech with 9spd shifter or viceversa).
Front mech a bit more tricky. The cable pull required for shimano road front mechs is different to that required for shimano MTB front mechs. If you use a friction shifter then there will be no problem (e.g. old DX thumbie, etc). However, if you use an indexed MTB shifter it won't pull enough cable - you may get away with it on a double chainset but a triple will probably produce some problems. One bodge (from Chris Juden, CTC) to get around this is to put the gear cable on the bike side of the bolt that clamps it to the mech, thus lessening slightly the length of the mech arm. Alternatively just get a new front mech - should be able to pick up a good used one for a fiver.