Diet:
Now I have more time to look at your first post. I will difently change the breakfirst of yours. Go with something like oat meal or cereal with eggs. You probably don't have much time in morning, but it is a crap you are eating. I am not sure how much calories you need a day to maintain your current size. Meaning no change in muscle mass or fat. The easiest way to increase your calorie intake a day is to double your serving size or add a little something to each meal. For example, you can add baked poteto with these tuna your taking. Or make it tuna sandwich adding bread to it. Or you can double it to 2 cans. ALso make sure to get at least a gram of
protein per lb. Since you are 150 lb try to get at least 150 gram of
protein a day. I personaly go pick up
whey protein powder. It makes so much easy to meet this goal. ALso, your goal is to add the size try to consume 1.5-2 gram of carb per your body weigth. Based on the meal plan you wrote you seemed to eat very little carb or fat. I would start eating some complex carbs like brow rice you mentioned. I persoanlly like 40:40:20 (
protein:carb:fat ) but it is something you need to play around and find out what ration works best for your for your goal. Of course, it is different when you cutting. Stick to the same diet for two weeks, and if you dont gain muscle at all, I will bump up total calories, maybe 10% up. The diet is bascially trial and error. You have to play around to see what kind of food and how much is the best for you.
"Im not really sure what you mean by 500- 1000 above maintenance level?" If you eat, say 2500 calories a day, it wont change your weight ( no fat/musccle gain or loss) that is your maintenacne calorie. Try to eat 3000-3500 calories a day to gain some weight.
Supplements:
Ahhh supplements.

I dont know how much money u want to spend it, but follwoings are ones I feel you cannot go wrong. You might want to invest in
whey protein powder, multi vitamines, and
creatine. If you have an additon doe, check out some essential fatty acid. I have never took wieght
gainer, but they are
loaded with sugars. It might work well as a post work out meal, though, but other times it has too much simple carb in them.
Workout:
Therer are so many things you can do. I think there are training section on this board. Go check it out. The most important thing is learn how to lift right. If you doing bicpet curl, but using shulders and buck muscle. There msut be something wrong with your technique. ALso remmeber to use right weight.
You are just back to lifting again so I assume you will repsonse to pretty much any program you pick at this point. Stick to current one for maybe another 8 weeks or so and see where that will take you. Remeber if it aint broken....