on-camera flash vs. strobes with similar GN

Dear friends--

I have recently received JTL kit consists of 2-300w strobs (an

umbrella and a softbox). As I went through the manual I realized that

its GN is 54m (ISO 100). I already have canon 550EX kit (2 flashes

and an on-camera transmitter). Its GN is 55m (ISO 100). Should I

prefer the JTL kit on the 550EX for portraits and small objects still

life. Do you recommend that I buy stands and two 44'' umbrellas for

the 550EX kit and return the JTL kit.

BTW, be adviced that the sync cord of the JTL kit does not match my

camera (Canon 10D) nor my light meter (Sekonic L- 358).

Do you konw what I need to buy to trigger the strobes wirelessly from

the camera and the light meter?

Thanks

Use all 4. Your monolights have a built in optical slave. Use your ste-2 transmitter to fire your 550 ex's set on manual with ettl disabled and you're in business. Or keep your monolights for indoor use and use the 550ex's on location since they're battery powered.

There's probably some sort of adapter for the sync chord.