Here's a structure where 1C is Ms or Big (MOB perhaps?):

1C: 10-13 4-4+ in the majors OR 17+ balanced OR 19+ any
1D: 14-18, no 4cM, 15-16 if balanced
1M: 14-18, 4+, 14-16 if balanced
1NT: (11)12-14, no 4 or 5cM if 14, not 4-4 in majors
2X: 10-13 (or great 8-9) 5+, unbalanced, if 2M not 5-4/4-5 in majors
2NT: 5-5+ in majors (if 5-5, great suits), 10-13

Design here is keyed on:

a) opening 1NT or 2X on most hands below 14.

b) have the 1D and 1M as semi-power bids: showing at least 14 so opponents have danger in getting into the bidding - 1M can force the opponents into overcalling 1NT or 2X if they want to get in.

c) have 1M as 4 card majors with power (14+) but limited (less than 19) - this allows a structure for opener to unwind the hand types. In particular 1M-1NT;-2M is like the 2M opening, but 14-16, and opener passes 1NT if 14-16 balanced, or after 1H-1NT with 5Hs and 4Ss 14-16.

d) since 1D denies 4cM, 1D-1M is 5+, and, if the opponents interfere over 1D, negative doubles do not need to be used - instead of pure penalty I prefer value showing doubles that are passable - with a pure penalty pass and wait for opener to reopen with a double - these value showing doubles promise two or more of the slow cards (KQJT) in the opponents suit and 3 or 4 of the suit.

e) 1C has a nice split - if the opponents hope in, responder will usually be able to read whether opener is the 10-13 or the big hand type. If the opponents jump in a major, double says pass with major, bid if strong and not the major. If the opponents jam in the minor, double is negative getting values into play and finding major contracts.

f) 2X is based on the Fantoni-Nunes framework, which I love. Daniel Neill continues to do wonderful work on bidding systems, including these notes on Fantoni-Nunes:

http://www.geocities.com/daniel_neill_2000/sys/Fantoni_Nunes.txt

In arriving at the MOB design, I went through a lot of permutations like usual, as I showed in the "Messy" posting, but once was enough for blogging the messy design process.

If you don't like the loss of transfers after the 1D opening, play:
2m: 10-14, no 4cM if 14
1D: 15-18, no 4cM
--1H shows 5+Ss, 1S shows 5+Hs - legal in ACBL since 1D is 15+