Well here's a list of codes from Gameshark for this game
Code:
[M] Must Be On
9032B87FA001
A14CAD62C569
27BFE4835184
Have 50,000 Zenie
0CB85EB49F02
Have all Items
EB483D320586
C9483F24E5C4
Have all Equipment
EEB3F5C8B6D0
728C20A0B5CD
84376F03028D
Goku:
Inf HP
FA2BB161D3E0
Max HP
F77EE14373E9
Inf EP
F63EE141D3E9
Max EP
F36FA16373E9
Inf KI
F22FA161D3E9
4FD07E9360E6
Inf SP
A43EED75A70B
A57EED77070B
Max XP
FB69914A5BF4
F36F816B0BD9
Max STR
200D844DA529
Max POW
600D8448A5E9
Max END
214D844F0529
Max SPD
614D844A05E9
999 Stat Points
EB6B9D5B63D2
Skill Level #2
0CB2FEF5F602
408C2EA655CD
Gohan:
Inf HP
7285A0E1C0E9
Max HP
EF50FD5370E2
Inf EP
EE10FD51D0E2
Max EP
EB41BD7370E2
Inf KI
EA01BD71D0E2
E754ED5370EB
Inf SP
2C90FCF5B402
2DD0FCF71402
Max XP
53ED028A4BF9
5BEB12AB1BD4
Max STR
98891B9DB526
Max POW
D8891B98B5E6
Max END
99C91B9F1526
Max SPD
D9C91B9A15E6
999 Stat Points
53EF028B73DD
Skill Level #2
B4366125E60D
408C2EA655CD
Goten:
Inf HP
6AABBCF2E3A2
Max HP
67FEECD043AB
Inf EP
66BEECD2E3AB
Max EP
63EFACF043AB
Inf KI
62AFACF2E3AB
7FFAF0C043A0
Inf SP
943E6326874D
957E6324274D
Max XP
CB431F1978B2
C3450F38289F
Max STR
10270A1E866F
Max POW
50270A1B86AF
Max END
11670A1C266F
Max SPD
51670A1926AF
999 Stat Points
DB4113084094
Skill Level #2
3C9870A6D544
408C2EA655CD
Trunks:
Inf HP
C2052F32F0AF
Max HP
DF50730050A4
Inf EP
DE107302F0A4
Max EP
DB41332050A4
Inf KI
6AABBCF2E3A2
67FEECD043AB
Inf SP
1C9072A69444
1DD072A43444
Max XP
63ED8CD96BBF
6BEB9CF83B92
Max STR
0809160E8564
Max POW
4809160B85A4
Max END
0949160C2564
Max SPD
4949160925A4
999 Stat Points
C36F0F18439F
Skill Level #2
24B66CB6D64F
408C2EA655CD
Vegeta:
Inf HP
5AAB32A3E3E4
Max HP
57FE628143ED
Inf EP
56BE6283E3ED
Max EP
53EF22A143ED
Inf KI
52AF22A3E3ED
CF7A7F1153E6
Inf SP
04BE6EB7970F
05FE6EB5370F
Max XP
7BC390C868F4
73C580E938D9
Max STR
A0A785CF9629
Max POW
E0A785CA96E9
Max END
A1E785CD3629
Max SPD
E1E785C836E9
999 Stat Points
6BC19CD950D2
Skill Level #2
8C18FF77C502
408C2EA655CD
Gotenks:
Inf HP
F22FA163F3E9
Max HP
4FD07E9140E6
Inf EP
4E907E93E0E6
Max EP
4BC13EB140E6
Inf KI
4A813EB3E0E6
47D46E9140EF
Inf SP
AC3AFD778702
AD7AFD752702
Max XP
F36D81487BFD
FB6B91692BD0
Max STR
3809985F8522
Max POW
7809985A85E2
Max END
3949985D2522
Max SPD
7949985825E2
999 Stat Points
F36F814943D9
Skill Level #2
14B6E2E7D609
408C2EA655CD
Vegito:
Inf HP
EA01BD73F0E2
Max HP
E754ED5150EB
Inf EP
E614ED53F0EB
Max EP
E345AD7150EB
Inf KI
E205AD73F0EB
FF50F14150E0
Inf SP
3494E0E79409
35D4E0E53409
Max XP
4BE91E986BF2
43EF0EB93BDF
Max STR
908D0B9F952F
Max POW
D08D0B9A95EF
Max END
91CD0B9D352F
Max SPD
D1CD0B9835EF
999 Stat Points
5BEB128953D4
Skill Level #2
BC327127C604
408C2EA655CD
Gogeta:
Inf HP
62AEACD0C3A2
Max HP
7FFBF0E263A9
Inf EP
7EBBF0E0C3A9
Max EP
7BEAB0C263A9
Inf KI
7AAAB0C0C3A9
77FFE0E263A0
Inf SP
9C3B7304A74D
9D7B7306074D
Max XP
C3460F3B58B2
CB401F1A089F
Max STR
88A217ACB66D
Max POW
C8A217A9B6AD
Max END
89E217AE166D
Max SPD
C9E217AB16AD
999 Stat Points
43C40EBA7096
Skill Level #2
A41D6D14E546
408C2EA655CD
There's Inf Sayan bars on Codebreakers, but since CMP doesn't have anyone hacking/converting codes for GBA, and Gameshark Forums go offline now and then for some odd reason, (that and the fact that no one there owns the game, and thus cannot hack it) there's not much you can do, unless someone can convert them...course if you use the Max KI you may not have much problems with Super Sayan running out.
edit: I'd also like to point out, that despite having over 9000 HP is possible, (just save the game with the Max HP code on, level up once, and boom. You'll have over 9000 HP.) you'll more than likely end up with negative HP, and thus being unable to continue with the game, as you'll constantly die.
Have All Items also gives you Key Items, and the Equipment gives you one of every piece of equipment. A bit helpful, especially if you're trying to find those Ton Armband/Boots. But do NOT sell ANYTHING off! If you do, and try to equip something, the game will crash. It's happened to me before, and it's annoying as hell. ¬.¬