Ring flash advice/decision

[topcatproduction]

I'm getting into macro photography with insects etc and use a 100mm pentax macro with ext tubes, I think a ring flash would be my best option rather than a wobbly big rig towering over the lens as I like to shoot out and about and it just aint practical!
Its a shame this gets such a bad review as it has the features I want http://www.amazon.com/Opteka-RL-500-Macro-Flash-Digital/dp/B000ROD754

Otherwise I would be considering the Marumi http://www.amazon.co.uk/Marumi-DRF14-Canon-Ring-Flash/dp/B0012MGQ62/ref=sr_1_1?ie=UTF8&s=electronics&qid=1255085069&sr=8-1
but dont like the way it has no manual option or controls. Would this be a problem with me using my completely manual lens? I could dim it a bit using masking tape or similar but would like some opinions please!

[topcatproduction]

Ok having trouble with getting advice here! By looking at other posts I'm thinking about using an off camera flash instead of a ring (as I cant afford a decent ring anyway!) and looking at 2 choices, if you care to put your thoughts in its much appreciated- I need some help!

I will make up a bracket and use an off camera cord but the 2 flashes I have looked at and should be able to afford are:

1. Speedlite 540EZ - should work in manual mode only (?)

2. Speedlite 420EX - which I gather is an ETTL (automatic) flash only (?)

I am using an old MANUAL pentax macro lens so thinking that spending money on an EX flash may not be worth it unless I fork out on one which has manual settings for my macro work too. What do you think?

[TooManyHobbies]

Ring isn't very good for very close marco. The twin is awesome. You can point in from each side and adjust depending on how close you are. I've also rigged up my 580 and it did a decent job, but with the 24EX you can slave the 580 for background lighting. I've even used my super powerfull strobes with a softbox. The 24EX is a little harsh for lighting so I put diffusers on it. Same with the 580. The powerful strobes did the best job of soft light for macro, but they work better in studio then outside moving around.

You are not going to get consistant results with metering so will have to adjust or shoot manual anyway when you get super close with regular flashes.