I have read loads of forums on this, can someone please clarify something for me?

With with the Laney LC 30 or the Marshall DSL 401 will I need an overdrive or distortion pedal in order to get a metal tone suitable for metallica type of stuff or will the amp's od be sufficient, I tried only the marshall and it sounded great but it was with a pacifica, I have a fender strat.

It really depends on what sound you're looking for.
If you want a flat-out metal tone I think the DSL401's OD/2 channel gives more than enough gain.
I myself prefer the more "vintage" metal/rock tone, so I use an overdrive pedal in conjunction with the DSL's OD/1 channel.
What I would recommend is to try the amp on the OD/2 channel, cranked as much as possible. That's the only way you'll be able to tell if it can supply the tone you need without a pedal.
Gibson Les Paul Studio w/ EMG 81/85
Fender American Vintage Series '52 Telecaster
Marshall JCM2000 DSL401
Roland MicroCube
Dunlop ZW-45 Wah
Dunlop Rotovibe
Dunlop MXR EVH Phase 90
Dunlop MXR Zakk Wylde Overdrive
Boss CE-5
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