2fat-
Sounds like you are going down the right path. I would hit the cardio hard before your hit the gear. That way you'll be pretty lean before you start the gear and you can reduce cardio. This will help keep your muscle gains. Here is a good strategy:
Find something to do like cycling, walking (hey it burns cals), running inside or out, or swimming. Shoot for 5 hours a week. If you have a heart rate monitor stay in 65-75% of your max HR (~130-160bpm) or a pace that is quick, but allows you to carry on a conversation w/someone. This is the fat burning zone-if you can't talk you are going too hard and burning more carbs (general rule of thumb). When exercising at lower intensities your body will burn fat because fat has lots of stored energy (1g of fat=9 cals, 1gm of carb=4 cals), but you need some carbs to initiate that fatburning process. As your exertion levels increase and you need energy faster, your body shifts to easier-to-burn carbs. However it stills burns some fat. Carbs=easier to burn, but less energy. Fat=hard to burn, but more energy.
Don't go on a low carb diet. Stay around 50-60% carbs, but take in a lot of protein, like 30-35%. This will help keep muscle. You need carbs for cardio. Your body will use carbs to burn fat or if you are putting out a lot of effort it will just burn carbs and a small amount of fat. Also don't drastically restrict your calories. If you starve yourself you tend to loose water, catabolize muscle, and pack on fat. Your bod will go into survival mode and store fat while burning off all availible glucose and it will start to burn protein (muscle). Protein is hard to burn and only has 4 cals/energy per gram, but your body would rather burn muscle and save fat for later in extreme cases.
Count your calories. Create a 500cal/day deficit, i.e. if you expend 5000cals (Basal Metabolic Rate + cals burned by exercise) consume 4500cals. A pound of fat is 3500cals. 500cals/day deficit x 7 days = 3500cals or 1 pound of fat. This is a conservative schedule. You could loose 2 pounds a week safely.
You can loose more, but unless you take DNP (or a similar mitochondrial uncoupler) it won't be fat. T3 would work, but you should try and loose most of your BF with cardio first. Pharmaceuticals will be most effective on taking off those last few pounds-save them for later (also you need to handle DNP and T3 carefully-save'em for those special occasions). Actually you could incorporate ECA; it will help with fat loss and appetite suppression. Crash diets usually lead to water weight loss and muscle catabolism. Low carb diets work if you really dial them in and know your body, but they will leave you drained for cardio and you can loose more fat with diligent cardio.
Hope this gives you some more detailed info. You can email me if you want more detailed info. This stuff is all pretty general. I always have to loose BF and conserve muscle in my offseason training. I haven't tried any supps (other than ECA) and can usually get below 8% easily. I'm pretty lean and do TONS of cardio for triathlon, but I also need lots of muscle. Good luck.
FHG